A portable biosensor system comprising a measurement device with a computer, and a sensor chip that can be installed in this measurement device, has been used in the past to measure the concentration of an analyte in a blood sample, such as the blood glucose concentration (glucose value). The concentration of the analyte is calculated on the basis of the amount of oxidized product and reduced product produced by an enzyme cycling reaction via a redox enzyme in which the analyte serves as the substrate. The speed of the enzyme cycling reaction depends on the temperature of the environment in which the reaction takes place (the reaction temperature). Accordingly, a biosensor system has been proposed that comprises a function of correcting the concentration of an analyte on the basis of the reaction temperature. The reaction temperature is measured, for example, by a temperature sensor disposed in the measurement device (Patent Literature 1).